The overall goal of this Laboratory Program is to produce libraries of natural product-derived substances by innovative methods and to evaluate these in "Smart" bioassay systems targeted to cancer. Despite intensive effort in many fields of science and medicine to find effective treatments for this complex family of diseases, the incidence and morbidity due to cancer continues to look very bleak. This Laboratory Program will focus on the unique chemistries of marine cyanobacteria, and will integrate with the efforts of the other laboratory programs of this Program Project Grant application to clone natural products biosynthetic genes and over express these in a convenient host organism, Streptomyces venezuelae. Four parallel tracks will be taken in this pursuit: 1) our laboratory will provide cultured marine cyanobacteria to Laboratory Program #1 for genomic DNA insolation and subsequent combinatorial biology efforts in Laboratory Program #2; 2) our laboratory will provide information to Laboratory Program #2 on biosynthetic pathways and partial protein sequences of key "tailoring" enzymes to aid in the cloning of genes of specific marine cyanobacterial metabolites of high relevance to cancer and diversity generation; 3) our laboratory will integrate with Novartis "Smart" assays (Laboratory Program #3) to isolate and structurally define new lead compounds deriving from the above integrated molecular biological approaches; and 4) our laboratory will use unique tailoring enzymes cloned from marine cyanobacteria and modified by protein engineering techniques to biotransform additional natural product structures of cancer relevance. Diode-array HPLC methods will be used to dereplicate parent structures, known compounds, and nuisance substance in the combinatorial biosynthetic libraries showing activity in the Novartis "Smart" assays.